Fiber in-situ synthesis of calcium silicate for usage in fine paper
This paper researches fiber in-situ synthesis of calcium silicate that is made from sodium silicate solution extracted from fly ash, lime milk and fiber and its usage in fine paper. The in-situ synthesis technique was used to prepare man-made calcium silicate loaded in paper. The paper is in line with the copy paper standards. The experiments determined the optimum conditions for papermaking as follows, the pre-processing time of fiber immersed in the silicon solution 6h, pulp freeness 42°SR, the SiO2 concentration of the silicon solution 65.5g/L, the effective calcium concentration milk of lime 175g/L, stirring speed 550r/min, the reaction temperature 95°C, the reaction time 90min. Under these conditions, the filler retention rate in fine paper can reach more than 80%. A scanning electron Microscope-Spectroscopy (SEM-EDX), X-ray diffraction (XRD), infrared spectroscopy (FT-IR) was used to analyze paper products and structure. The results showed that the calcium silicate generated within the cell lumen, cell wall, and other open spaces of the fibers, and good bonding was demonstrated between the filler and fibers.